Multiple contact switch



M. A. AusMAN m' Ax. 2,501,431

mum: coN'rAcT'swITcH Mud. 12,1, 195o Filed June 26, 1947 n will-lY INVENToRs M//anA/msf/ Vince/rf C awfr ,4/f #andere ATTORNEYS Patented Mar. 21, 1950 4UNITED STATES PATENT OFFICE MULTIPLE CONTACT SWITCH Milton A. Ausman and Vincent C. Davis, Oakland, and Alf Hundere, Richmond, Calif., asslgnors to California Research Corporation, San Francisco, Calif., a corporation of Delaware Application June 26, 1947, Serial No. 757,228

4 Claims. (Cl. 200-11) This invention relates to electrical circuit switching means, and more particularly to a movable contact rotary switch adapted to open or close a plurality of circuits in sequence and'at a relatively high rate`of speed.

The principal object of the invention is to provide a device of this nature having a plurality of single pole contacts which are connected or disconnected ln sequence at a rate of several hundred times a minute, the duration of such contacts being closely controlled and means being provided for preventing utter or bouncing of the contacting members under such conditions of operation.

Another object is to provide a rotary multiple contact switch which may be made of very light materials suitable for use in guided projectiles and similar applications.

These and other objects and advantages will be further apparent from the attached drawing which forms a part of this specification and from the following description of a preferred embodiment of the invention.

In the drawing,

Figure 1 is a longitudinal sectional view of a multiple contact switch embodying the invention.

Figure 2 is a transverse sectional view on an arc represented by section line II--II of Figure 1.

Figure 3 is a transverse sectional view on an arc represented by section line III-III of Figure l.

Figure 4 is an end vertical sectional view on line IV-IV or' the arrangement shown in Figure 1.

Referring to the drawing, reference numeral Il designates generally a base to which is secured a bracket I I carrying a bearing I2 for shaft I2. which may be driven through coupling I4 by means of a motor or other prime mover, not shown.

An insulating board I5, which forms a main support for one group of the contacting elements to be described, is suitably secured to base I and is provided Awith a circular opening l5 on one side of which is a concentric annular recess I1. A plurality of circumferentially spaced fixed contacts, in this case designated by members It, extend through the insulating board I5, the inner ends of contacts i8 projecting outwardly into recess Il. An annular disc I9, preferably of a spring metal such as phosphor bronze, is secured by screws to board I5 to overlie the recess I1 and the contact faces of members Il. In this embodiment a plurality of radial slots 2| 2 zoidai cantilever spring fingers opposed to contacts I8 and spaced therefrom the desired distance to be out of contact therewith. v

A rotor generally designated 23 is secured to shaft I 3 to be concentric with the annular disc I 9 and contact members 22. An insulating bushing 24 on rotor 23 serves to electrically isolate the several parts which are secured thereto. A roller 25 is supported on bushing 24 by a flexible radial member 26 to overlap the inner ends of contact fingers 22 and is adjustable by means such as screw 21 to be moved toward or away from the plane of said contact fingers. In this example, roller 25 is illustrated as being a small ball bearing assembly. On the opposite side of the radial flange of bushing 24 is a disc 2l carrying a radially extending cam generally designated 29 which is opposed to roller 25 on the opposite side of the plane of spring contact members 22. A recess 30 is provided along the leading portion of cam member 29 so that roller 25 willbe effective to displace a single spring finger 22 toward the cam member thereby also closing the contact between that finger and its corresponding contact member I8. The trailing face 3i of cam 29 is more nearly in the normal plane of members 22 so that after a finger 22 is displaced by roller 25 the transition between the recess 31| and the trailing face 3| will be effective positively to move that spring finger back to its normal or disconnected plane. Desirably, the trailing face 3| is of such a circumferential dimension that it provides a d-well surface which acts to damp out vibrations which may have been set up in spring finger 22 by virtue of its initial deflection under roller` 25 and its subsequent return to a normal position.

If this were not provided the spring linger would normally oscillate and finally return to its released position at a rate depending upon its natural period and internal damping. It is normally impracticable to so design the length and width of the fingers 22 to produce sufiicient spring action to overcome their own natural inertia to follow the deflecting means, in this case the roller 25, so that the cam 29 with its two surfaces just described acts positively to restore the contact element to its normal plane without flutter or undue time lag.

In order to adjust the circumferential relation between roller 25'and the several parts of cam 29, it is desirable to provide means such as slots 32 and screws 33 connecting bushing 24 with the cam follower disc 28 (Figure 4).

are formed in disc Il to provide generally trape- Il VReferring again to the drawing, specifically Figures 2 and 3, the action of roller 2l upon a given contact nnger 22 to urge `it toward or against cam 2l is illustrated by the first of those figures. Figure 3 is a sectional view taken on the arc of contact members Il and illustrates how only one of the spring ngers 22 is deflected at this point from its initial position. in this case to complete the contact between plate Il and a given member Il, by the combined action oi' the roller and cam .lust described.

Although the present arrangement illustrates a multiple contact switch in which the contacts are normally open and are closed sequentially by the rotation of rotor 2l, it is obvious that a simple reversal of parts would provide the opposite action, namely where the contacts were normally closed and opened in sequence by the action of the rotor 2l, roller 25 and cam 29. Similarly the individual contact fingers 22, represented in this example as being formed by slotsin a unitary plane annulus of spring sheet metal could equally well be discrete or separate segments secured to a plane insulating base such as plate i5. It is also apparent that, if a longer contacting time is desired without modifying the circumferential dimensions of fingers 22, roller 25 and cam 2l, adjacent groups of the fixed contacts Il could be shunted by suitable connectors. Also, the relative position of the slots in the annulus could be reversed to its outer periphery, with a corresponding reversal of the roller and cam location.

Under certain conditions of relatively low speed operation it has been found that certain of the advantages of the present invention can be obtained without the use of the cam member, particularly if the natural period of the spring iingers is chosen so that adequate contacting action can take place under the influence only of the roller or initial deilecting means for the contact devices.

In conclusion, it will be understood that this invention comprehends broadly a multiple contact switching mechanism characterized by a plurality of coplanar contacting members in combination with a first continuously moving means for deflecting said contact members in sequence in one direction and a second continuously moving means, displaced circumferentially with respect to the first means, for deilecting the contact members in the opposite direction independently of the natural frequency of the individual contact members acting as cantilever springs. Under certain circumstances outlined above, the second continuously moving contact deecting means Just mentioned may be omitted. Although a single example of this invention is illustrated, it is to be understood that numerous changes and modifications could be made in addition to tho suggested above without departing therefrom and all such as are within the scope of the appended claims are embraced thereby.

We claim:

i. A circular multiple contact switch comprising a plurality of coplanar exible contact fingers comprising radial segments formed in a unitary plane annulus of spring metal, a corresponding plurality of contact points opposing said ilngers. a continuously rotating means adapted positively and sequentially to move said fingers in one direction relative to said contact points, and a follower means circumferentially spaced from said first means and on the opposite side of said fingers to move said fingers in the opposite direction relative to saidc'ontact points and independently of the` vibration characteristics of said fingers.

2. A switching mechanism of the type described characterized by a plurality of coplanar contacting members, a nrst continuously moving means for sequentially deilecting said contact members in one direction and a second continuously moving means for subsequently deiiectmg said contact f members in the opposite direction, said second'- named means being provided with a dwell surface to damp vibration of said contacting members due to said deilections.

3'. A circular multiple contact switch comprising a plurality of coplanar flexible contact fingers, a corresponding plurality of contact points oppos ing said fingers, -a continuously rotating roller adapted positively and sequentially to move saidl fingers in one direction relative to saidcontact points, and a cam follower means circumferentially spaced from said roller and on the opposite side of said fingers, said cam having a recessed face opposite said roller followed by a raised face in its direction of rotation to move said fingers in the opposite direction relative to said contact points and independently of the vibration characteristics of said fingers.

4. A multiple contact switch according to claim 3 with the addition of means for adjustably positioning said cam circumferentially with regard to said roller.

MILTON A. AUSMAN. VINCENT C. DAVIS. ALF HUNDERE.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 404,867 Ricketson June il, 1889 1,580,882 Gent Apr. 27. 1926 2,454,646 Gates Nov. 23, 1948 

